Microchips have become prevalent in virtually all types of industries, and the demand for microchips has skyrocketed over the last ten years. This has placed pressure on the industry to make more and better chips as the need for microchips continues to rise. A chip connects to a motherboard or other device via a plurality of pins or terminals, which allows the board to communicate with the chip's logic or memory. An example of such a chip may be a memory card or processor for a computer, each of which may be insertable into a particular slot or socket that makes one or more electrical connections with the chip.
Part of the manufacturing process of the chips is the post-production testing of the quality and performance of the chip. Testing helps to diagnose problems in the manufacturing process, and improve production yields for systems that incorporate the chips. Therefore, sophisticated test systems have been developed to ensure that the circuitry in the chip performs as designed. A randomly selected chip is obtained from a production batch and attached to a tester or test socket. The selected test chip is referred to as a device under test, or “DUT.” The test socket is connected to a test apparatus that sends signals to the chip and evaluates the responsiveness and effectiveness of the chip as manufactured. In general, it is desirable to perform the attachment, testing, and detachment as rapidly as possible, so that the throughput of the tester may be as high as possible.
The test apparatus accesses the chip's circuitry through the same pins or terminals that will later be used to connect the chip in its final application. Accordingly, it is preferable that the test apparatus establish a reliable electrical contact with the chip's various pins or terminals so that the pins are not damaged, while maintaining a sound electrical connection with the pins. Most test apparatus of this type use mechanical contacts between the chip pins and the contacts on the test apparatus, rather than a more permanent attachment of the chip to the tester. When the chip is inserted in the test socket and coupled electrically to the test apparatus, each pin on the chip is engaged mechanically and electrically with a corresponding electrical connector on the test apparatus.
Preferably, the testing procedure involves as little mechanical wear on the chip and the test apparatus as possible during the attachment, testing, and detachment procedures. Typically, the test apparatus is designed to leave the chips in a final state that resembles the initial state as closely as possible. In addition, it is also desirable to avoid or reduce any permanent damage to the tester or tester pads, so that tester parts may last longer before replacement.
U.S. Pat. No. 7,918,669 to Tiengtum entitled “Integrated circuit socket with a two-piece connector with a rocker arm”, the contents of which are fully incorporated herein by reference, describes a test socket that can be used to couple the DUT with a test apparatus. The '669 Patent discloses a two piece connector that pivots when a test chip is placed on the socket so as to make contact between a contact pad on the chip and the another electrical contact on the test apparatus, enabling an evaluation of signal transmission by the chip. The platform houses a resilient tubular elastomer that biases the connector assembly in a disengaged position out of contact with the test apparatus. When the chip is placed on the socket, the linkage pivots and the bias of the resilient tubular member is overcome by the downward force applied by the chip, and an electrical connection is established across the connector assembly.
While the system of the '669 Patent has been proven effective in the testing of integrated chips, the wear on the test apparatus from the linkage leads to costly and time-consuming maintenance on the test equipment. The mount in the linkage is rigidly fixed in the test socket, and applies a non-compliant pre-loading on the test apparatus that can lead to excessive wear. In order to ensure a reliable connection, the mount was secured to the socket so as to be fixed.
Due to variances between the test equipment and the socket, it is possible that a gap can occur between the test equipment and the socket's electrical connector (mount). This gap can result in failed tests or improper measurements that can prolong the testing procedure and falsely suggest problems with the DUT. An improvement is needed to ensure a more reliable connection between the mount and the test equipment that does not result in excessive forces applied to the test equipment.